Clever ideas and fun implementation!
The character controls feel good, but I think the camera controls is not that great. Whenever you jump down from high for example, it always lag behind and don't let you see below. Audio is ok, but I feel like the music is a bit mismatched for the vibe of the game. Visuals are simple but cute.
When I play though, on web, the game usually lags when I'm falling down in the air. I don't know what causes it. I like the checkpoints system.
Overall a well polished entry. Good job!